Foam plastic tiles with flexible hangers



Sept. 5, 1967 E. J. KNAPP 3,339,325

FOAM PLASTIC TILES WITH FLEXIBLE HANGERS Filed March 25, 1964 INVENTOR EUGENE .J. KNAPP United States Patent 3,339,325 FOAM PLASTIC TILES WITH FLEXIBLE HANGERS Eugene J. Knapp, Corning, N.Y., assignor to Corning Glass Works, Corning, N.Y., a corporation of New York Filed Mar. 23, 1964, Ser. No. 353,762 7 Claims. (Cl. 52-609) even distortion so as to prevent such shrinkage or distortion from setting up stresses causing the tile edges to .warp

and peel away from adhesive securing the tile to a supporting surface.

Although the invention is described with and especially useful for ceiling tile, the principles are not limited thereto, and it is also applicable to other tile, larger panels and similar decorative or functional surface covering.

Some tile is made of a material having slow natural shrinkage or other uneven distortions in environmental use such as foam polystyrene, foam styrene acrylonitrile,

I green plywood and the like. Mounting of such shrinkable "tiles by means of known adhesive extending from edge to edge of the tile has not been satisfactory as the shrinkage and resulting distortion of the tile causes warping and attendant stresses, peeling the adhesive and causing the tiles to pop off the ceiling. Obviously a tile purchaser would be quite distressed with such results after installation and a product havingthese characteristics would fail.

With regard to the installation of a shrinkable tile secured to a supporting surface by adhesive means, the ambient atmosphere on the tile face causes slow natural differential shrinkage on the outside surface and this sets up stresses in the tile edges and tends to pull these edges down to relieve the stress. This stress will tend to peel the securing adhesive and will cause the tiles to pull loose from the mounting at their edges. It is the object of this invention to provide a tile or panel construction which, if subjected to shrinkage or shifting, will accommodate the same without causing the tile to distort or warp and pull loose from its adhesive adherence to a supporting surface.

Other objects and advantages of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

FIG. 1 is a perspective view of a ceiling with a plurality of tiles applied thereto.

FIGS. 2, a, b, and 0, illustrate the stresses and warpage that shrinkable tile is subjected to and how the tile peels away from its adhesive at the edges.

FIG. 3 is a perspective view of the tile of this invention.

FIGS. 4, a, and b, are sectional views showing the tile of this invention applied to a ceiling or other support before and after natural shrinkage.

Referring to the drawings, FIG. 1 illustrates a ceiling 10, although the invention is also applicable to other supporting structures for tile panels, and similar decorative or functional coverings, on which tiles 12 are mounted by adhesively securing the back of the tiles to the ceiling 10. If, however, the tile is constructed of a material which has a tendency to naturally shrink slowly and distort at a rate depending on ambient conditions e.g. relative humidity, it has been found that the edges will tend to 'pull away from the ceiling and peel away from an ad- "ice hesive. Similarly, if forces were applied to cause the tile to shift such as may be delivered by the supporting structure, the adhesive backing would be broken.

Referring to the problem of tile constructed of a material shrinkable or otherwise distortable in environmental use, such as from polystyrene, styrene acrylonitrile, green plywood and the like, FIG. 2 illustrates the problem involved with such constructions. In FIG. 20, length A indicates the adhesively secured length of the tile, while dimension B represents the free face length of the tile. Assume the tile is of a slowly naturally shrinkable material such as foam polystyrene or the like, after use for a time in ambient conditions the outer face of the tile will tend to shrink while the adhesive bond prevents the rear face of the tile from shrinking; thus the shrinkage of the tile will cause length B to become less while length A will remain constant. This situation is illustrated in FIG. 2b, wherein there is also illustrated the relative forces to which the adhesive is subjected by the arrows extending upwardly, the length of the arrows indicating the degree of force. As can be seen, the shrinkage of the tile sets up high forces tending to pull and peel the tile away from its adherence to a support at the tile edges. This will commonly cause the tile 12 to break away from the back or mounting surface 10 at its corners as shown in FIG. 20, and eventually fall from the ceiling, thus rendering the tile completely unacceptable for its intended purpose.

To provide an ideal mounting condition, the tile mounting media should be flexible enough to allow non-restricted movement of both faces of the tile while still being firmly adhered to a support, and thereby substantial stresses to the tile adhering adhesive are eliminated.

As shown in FIG. 3, the tile 14 of this invention is formed of a foam plastic material such as polystyrene although it could be other material to which the problem of this invention occurs, i.e. material subjected to shrinkage or tiles subjected to shifting forces, etc. The tile 14 may, as shown, include edges 16 and 17 for interlocking mounting with other tiles as shown in FIG. 1 so that each tile may be alternated for a pleasing optical effect. The tile in particular includes a unique flexible mounting means comprising a number of spaced apart resilient hangers. Hangers 18 are shown projecting from a back base 20 of the tile 14. These hangers are shown as cylindrical plugs, although other shapes could be used, and are small enough in diameter and have sufficient length to offer minimum resistance to deformation. That is, they are resilient or flexible and the end faces 19 of plugs 18 are all in the same plane so that the tile 14 may be secured to a ceiling 10 by means of adhesive on these faces 19 as shown in FIG. 4. Although in the preferred embodiment the plugs are integral with the tile plate, it is evident that the plugs could be in the form of a separate body or member positioned intermediate and adhesively secured to both the tile and supporting surface. The important feature is that the plugs form a flexible mounting between the tile and supporting surface to compensate and absorb any stresses set up between the two, and prevent the adhesive from failing.

When constructed of a semi-rigid foam plastic such as polystyrene the plugs are preferably initially compressed to a predetermined amount so as to make them resilient and flexible. The plugs actually recover most of their original size after compressing, but the compressing operation makes, such closed cell plastic foam materials more resilient. Although compressing of the plugs is desirable to obtain more resiliency therein, it is not absolutely necessary as the foam plastic in its original state has enough resiliency. The compressing of the plugs may be done by a roller during the manufacturing operation.

The end faces 19 of the plugs 18 may carry pressure sensitive adhesive precoated thereon so that the tiles may be immediately adhesively secured to a supporting ceiling although it is within the scope of this invention to use separately applied adhesive as is known in the art.

The plugs or hangers 18 must be suflicient in number as to provide substantial area by means of faces 19 for the particular adhesive used to secure the tiles to a particular support surface. By having a large number of plugs or hangers 18 the adhesive edge periphery is greatly increased allowing the tensile strength of the adhesive to be more eflicient to resist peeling.

FIG. 4 illustrates the tile of this invention applied to a ceiling 10. The tile has an outer face 22 which may be formed to provide acoustical properties. When mounted as shown in FIGS. 4a and 4b the flexible or resilient hangers or plugs 18 will initially be in the condition of FIG. 4a with the faces 19 of these plugs adhesively secured to the backing by pressure sensitive adhesive 21. As the polystyrene tends to shrink or if the shifting forces were applied thereto, such as by the support backing, the resilient plugs would allow both the face 22 and base 20 of the tile to shrink or shift so that undue shear stress would not be applied to the adhesively secured areas on the faces 19 of plugs 18. For example, if shrinkage of the tile body were to occur as illustrated in FIG. 4b, the plugs 18 would still stick to the same spots and would merely bend due to their flexibility or resiliency, and stresses would not be set up to the point that the tile would pull away from its supporting mount.

As an illustrative embodiment of a tile embodying the concept of this invention, individual tiles are constructed of foam polystyrene. The faces 19 of plugs 18 are precoated with pressure sensitive adhesive and a protective covering is placed over the adhesive, to be removed on use. The covering is stripped off when the tile is to be installed and the tile then pressed against a clean ceiling surface. The edges 16, 17 are not coated with adhesive as this would defeat the purpose of the invention. Also, adhesive on edges 16, 17 would hinder installation where one edge is slipped under another tile for interlocking purposes.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, it will be understood that various omissions and substitutions and changes in the form and details of the device illustrated, such as those described above may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. An improved mounting for maintaining adhesivelyapplied semi-rigid foam surface coverings securely attached to a mounting support wherein the surface covering has a tendency to shrink and otherwise distort upon exposure to various environmental conditions which comprises, a plurality of flexible, resilient precompressed foam plastic mounting bodies, adhesive means securing one face of said bodies to a mounting support, the end opposite said one face of said bodies being connected to the back face of a semi-rigid foam surface covering, and each of said bodies having a height suflicient to maintain the back of said surface covering in spaced-apart relationship with the mounting surface so that stresses produced in said surface covering may be absorbed by Said flexible mounting bodies and thereby securely maintain the surface covering adhesively sealed to the mounting support by said flexible mounting bodies.

2. An improved mounting for surface coverings such as semi-rigid foamed ceiling tile and the like having a tendency to shrink or distort under various environmental conditions which comprises, a plurality of flexible, resilient, precompressed foam plastic plug-like hangers, said hangers mounting a semi-rigid surface covering in spaced-apart relation with a support surface said flexible hangers extending between a back surface of the semirigid surface covering and said support surface, adhesive means engaging end portions of said flexible plug-like hangers for mounting said semi-rigid surface covering on said support surface, and said plug-like hangers being flexible along their extent while rigidly secured at both ends to absorb stresses set up in said semi-rigid surface covering and thereby prevent their transmission to the adhesive bond, thus maintaining a secure mounting.

3. A surface covering such as a tile or the like constructed of semi-rigid foam plastic subject to natural shrinkage comprising; a flat body including a front face and a rear base, a multiplicity of integral spaced-apart hangers constructed of flexible, resilient, precompressed foam plastic plugs extending outwardly from the rear base of the tile, each of the hangers having a flat outer securing surface in the same plane, said hangers having appreciable face area on the flat outer securing surfaces adhesive means on said flat outer securing surfaces securing the tile to a backing so that upon environmental factors placing shrinkage stresses or the like on an adhesive bond the resilient hangers will stretch and flex and an adhesive bond of the tile to the backing will not be subjected to suflicient stresses to cause peeling of the same.

4. A tile as defined in claim 3 wherein the adhesive means is a pressure sensitive adhesive.

5. A tile as defined in claim 4 wherein the foam plastic is foam polystyrene.

6. A ceiling tile of a naturally shrinkable semi-rigid foam plastic the tile comprising; a flat tile body including a front face and a rear base, a plurality of plugs of integral one-piece construction with and extending outwardly from the rear tile base, each of the plugs having a flat outer securing surface in the same plane, said plugs being precompressed after initial molding to render said plugs resilient and flexible and having an appreciable face area on the outer surfaces for securing the title to a suitable support, adhesive means carried by the face area of the tile for securing the same to the support, the natural shrinkage of the tile being compensated for by the resilient plugs which will stretch so that an adhesive bond of the tile to the support will not be broken.

7. A tile as defined in claim 6 wherein the plugs are cylindrical and the foam plastic is foam polystyrene.

References Cited UNITED STATES PATENTS 2,785,739 3/1957 McGregor- 161-150 2,931,214 4/1960 Maccaferri 52-390 X 3,000,144 9/1961 Kitson 52309 3,016,317 1/1962 Brunner 161-161 X 3,126,978 3/1964 Bergstrom 161-159 X FOREIGN PATENTS 476,678 1937 Great Britain.

JOHN E. MURTAGH, Primary Examiner. 

1. AN IMPROVED MOUNTING FOR MAINTAINING ADHESIVELYAPPLIED SEMI-RIGID FOAM SURFACE COVERING SECURELY ATTACHED TO A MOUNTING SUPPORT WHEREIN THE SURFACE COVERING HAS A TENDENCY TO SHRINK AND OTHERWISE DISTORT UPON EXPOSURE TO VARIOUS ENVIRONMENTAL CONDITIONS WHICH COMPRISES, A PLURALITY OF FLEXIBLE, RESILIENT PRECOMPRESSED FOAM PLASTIC MOUNTING BODIES, ADHESIVE MEANS SECURING ONE FACE OF SAID BODIES TO A MOUNTING SUPPORT, THE END OPPOSITE SAID ONE FACE OF SAID BODIES BEING CONNECTED TO THE BACK FACE OF A SEMI-RIGID FOAM SURFACE COVERING, AND EACH OF SAID BODIES HAVING A HEIGHT SUFFICIENT TO MAINTAIN THE BACK OF SAID SURFACE COVERING IN SPACED-APART RELATIONSHIP WITH THE MOUNTING SURFACE SO THAT STRESSES PRODUCED IN SAID SURFACE COVERING MAY BE ABSORBED BY SAID FLEXIBLE MOUNTING BODIES AND THEREBY SECURELY MAINTAIN THE SURFACE COVERING ADHESIVELY SEALED TO THE MOUNTING SUPPORT BY SAID FLEXIBLE MOUNTING BODIES. 